Why teams migrate

PostgreSQL offers superior JSON support, richer indexing options (partial, expression, GIN), better standards compliance, and no licensing concerns at scale.

Schema translation

  • AUTO_INCREMENT → SERIAL or GENERATED ALWAYS AS IDENTITY.
  • TINYINT(1) (MySQL boolean) → BOOLEAN.
  • DATETIME → TIMESTAMP WITH TIME ZONE.
  • MySQL ENUM → Postgres ENUM type or a VARCHAR with a CHECK constraint.
  • Backtick identifiers → double-quoted identifiers (or lowercase unquoted).

Data migration

pgloader is the standard tool for MySQL-to-Postgres migration. It handles type conversion, streams data, and can run live with CDC to minimise downtime.

LOAD DATABASE
  FROM      mysql://user:pass@localhost/mydb
  INTO      postgresql://user:pass@localhost/mydb
WITH include drop, create tables, create indexes, reset sequences;

Application changes

Update the connection string and driver. Test for MySQL-specific SQL: GROUP BY without full aggregation, LIMIT x,y syntax, IFNULL → COALESCE.